Two-pole SMT miniature housing for semiconductor components and method for the manufacture thereof

ABSTRACT

In a two-pole SMT miniature housing in leadframe technique for semiconductor components, a semiconductor chip is mounted on one leadframe part and is contacted to a further leadframe part. The further leadframe part is conducted out of the housing in which the chip is encapsulated as a solder terminal. No trimming or shaping process is required and the housing is tight and is capable of further miniaturization. The solder terminals as punched parts of the leadframe are conducted projecting laterally from the housing sidewalls residing opposite one another at least up to the housing floor which forms the components&#39; mounting surface. The chip mounting surface and the components&#39; mounting surface form a right angle with one another.

CROSS REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. § 120, this application is a continuation of andclaims the benefit of prior U.S. application Ser. No. 10/723,928, filedNov. 26, 2003 now U.S. Pat. No. 7,005,311, which is a divisionalapplication of and claims the benefit of prior U.S. application Ser. No.10/147,672, filed May 15, 2002, which is a divisional application of andclaims the benefit of prior U.S. application Ser. No. 08/866,064, filedMay 30, 1997, issued as U.S. Pat. No. 6,432,745 on Aug. 13, 2002, whichis a continuation of and claims the benefit of prior U.S. applicationSer. No. 08/681,599, filed Jul. 29, 1996, now abandoned, which is acontinuation of and claims the benefit of prior U.S. application Ser.No. 08/316,247, filed Sep. 30, 1994, now abandoned. The contents of theprior applications are incorporated herein in their entirety.

BACKGROUND OF THE INVENTION

The invention is directed to a two-pole SMT (surface mount technology)miniature housing in leadframe technique for a semiconductor component,whereby a semiconductor chip encapsulated in a housing is mounted on aleadframe part and is contacted to another leadframe part which isconducted out of the housing as a solder terminal.

In known SMT housings in leadframe technique, for example given a SOD123 housing, the solder terminals for the semiconductor component mustbe punched free and bent in a specific way after the encapsulation ofthe semiconductor component which, for example, occurs by casting,extruding or extrusion coating. This trimming and shaping process isnecessary in order to guide the solder terminals past the housing suchthat such SMDs (surface mounted devices) can be mounted on a printedcircuit board or mother board. The chip mounting area on the leadframein the mounted condition thereby proceeds parallel to the PCB (printedcircuit board), or to the mother board.

SUMMARY OF THE INVENTION

It is an object of the invention to create a SMT miniature housing for asemiconductor component that can be easily manufactured without such atrimming and shaping process, that is reliably tight and can also befurther miniaturized, and that is distinguished by a high heatelimination.

In a two-pole SMT miniature housing of the type initially cited, thisobject is achieved in that the solder terminals, as punched parts of theleadframe, project laterally from housing sidewalls lying opposite oneanother at least up to the housing floor that forms the components'mounting surface, whereby the chip mounting surface and the components'mounting surface form a right angle relative to one another.

Advantageously, the solder terminals have a thickness of approximately0.2 mm–0.5 mm. The SMT miniature housing is especially suited foroptoelectronic semiconductor components, particularly foroptosemiconductors that receive or transmit optical radiation at theside, referred to as sidelookers.

The two-pole SMT miniature housing is manufactured according to theinvention such that leadframe parts serving as finished solder terminalsin a leadframe are fabricated by punching, and such that thesemiconductor chip is then mounted on the one leadframe part and iscontacted to the other leadframe part. The semiconductor chip isencapsulated in a housing by casting, extrusion or extrusion-coatingsuch that the right-angled legs of the finished solder terminals at twooutsides of the housing lying opposite one another are conducted atleast up to the floor or mounting surface thereof. The finished SMTminiature housing then only has to be punched free from the leadframe.Components manufactured in this technique are then, for example,soldered onto a PCB such that the chip mounting surface residesperpendicularly relative to the PCB.

The advantages achieved with the invention are particularly comprised inthat the manufacturing step of trimming and shaping the solder terminalsis eliminated in the manufacture of the SMT miniature housing and isintegrated in the punching process for shaping the leadframe. The solderterminals—in their punched form as finished component parts—then onlyhave to be punched free from the lead frame. Resulting therefrom is thatbending stress is no longer exerted on the component and, for example,the occurrence of micro-cracks is prevented. Fewer deviations from thetolerances in the finished housing also occur since a bending of thesolder terminals is no longer necessary. The dimensional accuracy of thesolder terminals is thus especially improved. A corresponding leadframeshaping also makes it possible to avoid a deflashing of the terminalsafter their encapsulation. In particular, the dissipated power of thecomponents can be increased by employing thicker leadframes than inknown housings. Moreover, due to the improved arrangement of chip andleadframe or solder terminals, the housing can be further miniaturized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a SMT miniature housing in a side view;

FIG. 2 is a plan view onto the housing of FIG. 1;

FIG. 3 is another SMT miniature housing in a side view; and

FIG. 4 is a plan view onto the housing of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The two-pole SMT miniature housing shown in FIGS. 1 and 2 ismanufactured in a leadframe technique. A semiconductor chip is therebymounted on a leadframe part and is contacted to a further leadframe partwith a wire 4. The two leadframe parts are conducted out of the housing2 as solder terminals 3; for example, an IRED, LED or photodiode isencapsulated in the housing 2 as chip 1. The two solder terminals 3 arepunched as finished solder terminals 3 from the leadframe having thedesired contours in a punching process, and therefore need no longer beshaped afterwards. After the punching process, the semiconductor chip 1is mounted on the one leadframe part or solder terminal 3, and is thenencapsulated in plastic by casting, extruding or extrusion coating. Thetwo solder terminals 3, as punched parts of the leadframe, are therebyconducted at least up to the floor of the housing 2 that forms thecomponents' mounting surface, and project outwardly from housingsidewalls that reside opposite one another. The chip mounting surfaceand the components' mounting surface or bottom surface of the housing 2thereby describe a right angle relative to one another. The finished SMTminiature housing is then soldered onto a mother board or printedcircuit board 5 such that the chip mounting surface or the surfaceerected by the leadframe resides perpendicularly relative to the printedcircuit board 5 or relative to the PCB.

The two-pole SMT miniature housing shown in FIGS. 3 and 4 is employedfor optoelectronic semiconductor components having side-looking emissionor reception characteristics. Such components are also referred to assidelookers. The SMT-compatible housing is composed of the two leadframeparts that form the solder terminals 3 and that are punched from thelead frame in the desired shape. An optosemiconductor is mounted on theone leadframe part as a semiconductor chip, and is contacted to thesecond leadframe part or solder terminal part 3 via a bond wire 4. Thechip mounting can thereby also occur on a pre-housed leadframe. In thisexemplary embodiment, a space serving as reflector 7 is recessed in thehousing 2, the chip 1 being cast out therein with a transparent castingresin after the mounting so that the desired sidelooker is produced. Thechip mounting surface and the component's mounting surface again form aright angle with one another. The finished product, for example, canthen be soldered onto a PCB or onto a printed circuit board 5 such thatthe chip mounting surface resides perpendicularly on the surface that isformed by the printed circuit board 5. The soldering of the SMTminiature housing to a printed circuit board 5 is indicated with thesolder meniscus 6 in FIGS. 1 and 3.

Although various minor changes and modifications might be proposed bythose skilled in the art, it will be understood that we wish to includewithin the scope of the patent warranted hereon all such changes andmodifications as reasonably come within our contribution to the art.

1. An optoelectronic semiconductor chip component having a two-pole surface mount technology (SMT) miniature housing in lead frame technique, comprising: an optoelectronic semiconductor chip; a first lead frame part having the optoelectronic semiconductor chip mounted thereon at a chip mounting surface thereof and a second lead frame part being electrically connected to the optoelectronic semiconductor chip, a plastic housing partially surrounding the first and second lead frame parts and having a component mounting surface and a recess extending from a surface of the plastic housing to the chip mounting surface; said chip mounting surface and said component mounting surface being at right angles with respect to one another; said first lead frame part and said second lead frame part being conducted out of the plastic housing at opposite sides of the plastic housing and each having a leg portion outside the plastic housing for serving as a respective solder terminal running along the adjacent side face of the housing to the component mounting surface and extend to and terminate at the mounting surface; said first and second lead frame parts being punched parts such that during the entire method no trimming and shaping the solder terminals which exerts bending stress on the housing is carried out.
 2. The optoelectronic semiconductor chip component according to claim 1 wherein the solder terminals have a thickness of approximately 0.2 mm–0.5 mm.
 3. The optoelectronic semiconductor chip component according to claim 1 wherein the optoelectronic chip component has side-looking emission characteristics.
 4. The optoelectronic semiconductor chip component according to claim 1 wherein the optoelectronic chip component has side-looking reception characteristics.
 5. The optoelectronic semiconductor chip component according to claim 1 wherein the optoelectronic semiconductor chip is encapsulated with a casting resin inside the recess.
 6. An optoelectronic semiconductor chip component having a two-pole surface mount technology (SMT) miniature housing in lead frame technique, comprising: an optoelectronic semiconductor chip; a first lead frame part having the optoelectronic semiconductor chip mounted thereon at a chip mounting surface thereof and a second lead frame part being electrically connected to the optoelectronic semiconductor chip, a plastic housing partially surrounding the first and second lead frame parts and having a component mounting surface and a recess extending from a surface of the plastic housing to the chip mounting surface; said chip mounting surface and said component mounting surface being at right angles with respect to one another; said first lead frame part and said second lead frame part being conducted out of the plastic housing at opposite sides of the plastic housing and each having a leg portion outside the plastic housing for serving as a respective solder terminal running along the adjacent side face of the housing to the component mounting surface and extend to and terminate at the mounting surface; said first and second lead frame parts being punched parts such that during the entire method at transition regions from said first lead frame part and said second lead frame part to the respective leg portions no trimming and shaping which exerts bending stress on the housing is carried out.
 7. The optoelectronic semiconductor chip component according to claim 6 wherein the solder terminals have a thickness of approximately 0.2 mm–0.5 mm.
 8. The optoelectronic semiconductor chip component according to claim 6 wherein the optoelectronic chip component has side-looking emission characteristics.
 9. The optoelectronic semiconductor chip component according to claim 6 wherein the optoelectronic chip component has side-looking reception characteristics.
 10. The optoelectronic semiconductor chip component according to claim 6 wherein the optoelectronic semiconductor chip is encapsulated with a casting resin inside the recess.
 11. An optoelectronic semiconductor chip component having a two-pole surface mount technology (SMT) miniature housing in lead frame technique, comprising: an optoelectronic semiconductor chip; a first lead frame part having the optoelectronic semiconductor chip mounted thereon at a chip mounting surface thereof and a second lead frame part being electrically connected to the optoelectronic semiconductor chip, a plastic housing partially surrounding the first and second lead frame parts and having a component mounting surface and a recess extending from a surface of the plastic housing to the chip mounting surface; said chip mounting surface and said component mounting surface being at right angles with respect to one another; said first lead frame part and said second lead frame part being conducted out of the plastic housing at opposite sides of the plastic housing and each having a leg portion outside the plastic housing for serving as a respective solder terminal running along the adjacent side face of the housing to the component mounting surface and extend to and terminate at the mounting surface; said first and second lead frame parts being punched parts fabricated with no trimming and shaping at transition regions where said first lead frame part and said second lead frame part are conducted out of the housing to their respective leg portions.
 12. The optoelectronic semiconductor chip component according to claim 11 wherein the solder terminals have a thickness of approximately 0.2 mm–0.5 mm.
 13. The optoelectronic semiconductor chip component according to claim 11 wherein the optoelectronic chip component has side-looking emission characteristics.
 14. The optoelectronic semiconductor chip component according to claim 11 wherein the optoelectronic chip component has side-looking reception characteristics.
 15. The optoelectronic semiconductor chip component according to claim 11 wherein the optoelectronic semiconductor chip is encapsulated with a casting resin inside the recess. 